Determination of plasma homocysteine by high-performance liquid chromatography with fluorescence detection.
AuthorsJacobsen DW, Gatautis VJ, Green R
JournalAnal Biochem
PubMed ID2729575
Severe homocystinemia is frequently associated with vascular disease while the pathological consequences of moderate or slightly elevated plasma homocysteine are unknown. Cobalamin and folate deficiencies may result in an elevation of plasma homocysteine. A sensitive and reproducible assay for total plasma homocysteine has been developed. The essential steps in the ... More
Reactivity of mitochondrial sulfhydryl groups toward dithionitrobenzoic acid and bromobimanes under oligomycin-inhibited and uncoupling conditions.
AuthorsFreisleben HJ, Fuchs J, Mainka L, Zimmer G
JournalArch Biochem Biophys
PubMed ID2845867
Thiol reactivity was determined in rat heart mitochondria using chromophores of differing polarities: monobromobimane (MB), dithionitrobenzoate (NbS2), and bromobimane-q (MQ). The purpose of this study is to correlate reaction rates of protein thiols in the mitochondrial membrane with the oligomycin-inhibited and uncoupled states: In all cases investigated the reactivity of ... More
Analysis of biological thiols: determination of thiol components of disulfides and thioesters.
AuthorsFenton SS, Fahey RC
JournalAnal Biochem
PubMed ID2939769
This report describes a method for using selective cleavage of thioesters to allow differentiation between thioesters and disulfides. The method identifies thiol components (including glutathione, coenzyme A, and cysteine) of low-molecular-weight thioesters and disulfides in cell extracts, as well as thiols bound to protein via thioester or disulfide links. Thioesters ... More
Thiol-specific probes indicate that the beta-chain of platelet glycoprotein Ib is a transmembrane protein with a reactive endofacial sulfhydryl group.
AuthorsKalomiris EL, Coller BS
JournalBiochemistry
PubMed ID2934089
We used two membrane-permeable fluorescent reagents, monobromobimane and N-[[5-(dimethylamino)-1-naphthalenyl]sulfonyl]aziridine (N-dansylaziridine), and one membrane-impermeable fluorescent probe, monobromo(trimethylammonio)bimane, all three of which react selectively with protein thiols, to assess the presence of reactive sulfhydryls in the platelet glycoprotein Ib (GPIb) molecule and establish the topology of any GPIb-reactive thiols in the platelet ... More
N-acetylcysteine augments the cellular redox changes and cytotoxic activity of internalized mycobacterium bovis in human bladder cancer cells.
AuthorsPook SH, Esuvaranathan K, Mahendran R
JournalJ Urol
PubMed ID12131368
PURPOSE: We determined whether changes in cellular reactive oxygen species correlated with mycobacteria internalization and bladder cancer cell death. MATERIALS AND METHODS: Reactive oxygen species and thiols in RT112 and MGH bladder cancer cells were determined using the fluorescence probes 5-(and 6)-carboxy-2', 7' dichlorodihydrofluorescein diacetate and monobromobimane. Superoxide and nitrite ... More
An electrophoretic profiling method for thiol-rich phytochelatins and metallothioneins.
AuthorsFan TW, Lane AN, Higashi RM
JournalPhytochem Anal
PubMed ID15202602
Thiol-rich peptides such as phytochelatins (PCs) and metallothioneins (MTs) are important cellular chelating agents which function in metal detoxification and/or homeostasis. The variations in molecular sizes and lack of chromophores of these peptides make their analysis difficult. This paper reports an electrophoresis-based method for a broad screen of thiol-rich peptides ... More
Interaction of diphtheria toxin T domain with molten globule-like proteins and its implications for translocation.
AuthorsRen J, Kachel K, Kim H, Malenbaum SE, Collier RJ, London E
JournalScience
PubMed ID10320374
'The transmembrane (T) domain of diphtheria toxin has a critical role in the low pH-induced translocation of the catalytic domain (A chain) of the toxin across membranes. Here it is shown that at low pH, addition of proteins in a partly unfolded, molten globule-like conformation converted the T domain from ... More
Evaluation of methods for measuring cellular glutathione content using flow cytometry.
AuthorsHedley DW, Chow S
JournalCytometry
PubMed ID8026225
'The currently available flow cytometric stains for cellular glutathione were evaluated, examining the labelling of both human and rodent cell lines under various conditions of concentration, time, and temperature. Procedures were used that depleted glutathione (GSH) while having a minimal effect on other cellular sulphydryls in order to estimate linearity ... More
Identification of cytosolic leucyl aminopeptidase (EC 3.4.11.1) as the major cysteinylglycine-hydrolysing activity in rat liver.
AuthorsJösch C, Klotz LO, Sies H
JournalBiol Chem
PubMed ID12675513
'Cysteinylglycine hydrolysis is a step in the metabolism of glutathione and glutathione S-conjugates. We had previously observed that in rat liver the enzymatic activity is predominantly located in the cytosol. Here we demonstrate that cytosolic leucyl aminopeptidase (EC 3.4.11.1) is the major cysteinylglycine hydrolysing activity in rat liver. Evidence was ... More
Derivatization in capillary electrophoresis.
AuthorsBardelmeijer HA, Lingeman H, de Ruiter C, Underberg WJ
JournalJ Chromatogr A
PubMed ID9646486
'In recent years capillary electrophoresis (CE) has been developed into a versatile separation technique, next to gas and liquid chromatography (LC), well suited for the determination of a wide variety of e.g., pharmaceutical, biomedical and environmental samples. The main advantages of CE over chromatographic separation techniques are its simplicity and ... More
Comparison of three different fluorescent visualization strategies for detecting Escherichia coli ATP synthase subunits after sodium dodecyl sulfate-polyacrylamide gel electrophoresis.
AuthorsBerggren KN, Chernokalskaya E, Lopez MF, Beechem JM, Patton WF
JournalProteomics
PubMed ID11680898
'The correlation between protein molecular weight and the number of lysine or basic amino acid residues was found to be high for broad range molecular weight standards, subunits of Escherichia coli F1F0-ATP synthase and the translated open reading frame of E. coli. A relatively poor correlation between protein molecular weight ... More
Stress protein activation by the cyclopentenone prostaglandin 15-deoxy-delta12,14-prostaglandin J2 in human mesangial cells.
AuthorsZhang X, Lu L, Dixon C, Wilmer W, Song H, Chen X, Rovin BH
JournalKidney Int
PubMed ID14871400
'BACKGROUND: The cyclopentenone prostaglandin 15-deoxy-delta12,14-prostaglandin J2 (15dPGJ2) affects mesangial proliferation, survival and production of proinflammatory proteins. During a survey of the mesangial cell proteome after treatment with 15dPGJ2, heat shock protein 70 (HSP70) was found to be the most conspicuously up-regulated protein, suggesting that stress proteins are key mediators or ... More
Characterization and molecular cloning of a glutathione S-transferase from the whitefly Bemisia tabaci (Hemiptera: Aleyrodidae).
AuthorsRauch N, Nauen R
JournalInsect Biochem Mol Biol
PubMed ID15041016
'Glutathione S-transferases (GST) catalyzing the conjugation of reduced glutathione to a vast range of xenobiotics including insecticides were characterized in the whitefly Bemisia tabaci. GST activities were determined in susceptible and resistant strains of B. tabaci towards artificial substrates, i.e. 1-chloro-2,4-dinitrobenzene (CDNB) in a photometric microplate assay and monochlorobimane (MCB) ... More
Cysteine-containing peptide sequences exhibit facile uncatalyzed transacylation and acyl-CoA-dependent acylation at the lipid bilayer interface.
AuthorsQuesnel S, Silvius JR
JournalBiochemistry
PubMed ID7947742
'A variety of simple cysteine-containing lipopeptides, with sequences modeled on those found in naturally occurring S-acylated proteins, undergo spontaneous S-acylation in phospholipid vesicles at physiological pH when either long-chain acyl-CoAs or other S-acylated peptides are added as acyl donors. Fluorescent or radiolabeled lipopeptides with the sequence myristoyl-GCX- (X = G, ... More
Mycothiol biosynthesis and metabolism. Cellular levels of potential intermediates in the biosynthesis and degradation of mycothiol in mycobacterium smegmatis.
AuthorsAnderberg SJ, Newton GL, Fahey RC
JournalJ Biol Chem
PubMed ID9804803
'Mycothiol (MSH; 1-D-myo-inosityl-2-(N-acetyl-L-cysteinyl)amido-2-deoxy-alpha-D- glucop yranoside (AcCys-GlcN-Ins)) is a novel thiol produced at millimolar levels by mycobacteria and other actinomycetes that do not make glutathione. We developed methods to determine the major components of MSH (AcCys, Cys-GlcN, AcCys-GlcN, Cys-GlcN-Ins, GlcN-Ins) in cell extracts. Mycobacterium smegmatis was shown to produce measurable levels ... More
Antibody directed against the 142-148 sequence of the myosin heavy chain interferes with myosin-actin interaction.
AuthorsDan-Goor M, Muhlrad A
JournalBiochemistry
PubMed ID1703018
'It has been reported recently that the isolated and renatured 23-kDa N-terminal fragment of rabbit skeletal muscle myosin binds tightly to F-actin in an ATP-dependent manner [Muhlrad, A. (1989) Biochemistry 28, 4002-4010]. The binding to actin is of electrostatic nature and may involve a positively charged cluster of residues on ... More
The effects of monobromobimane on calcium and phenylarsineoxide-induced mitochondrial swelling and cytochrome C release in isolated brain mitochondria.
AuthorsAbe T, Takagi N, Nakano M, Tanonaka K, Takeo S
JournalBiol Pharm Bull
PubMed ID15056859
'A possible involvement of inhibitory effects of monobromobimane (MBM), a thiol reagent, on the swelling and the release of cytochrome c in the isolated brain mitochondria was examined. MBM dose-dependently inhibited the calcium and phenylarsineoxide-induced mitochondrial swelling and cytochrome c release. Significant relationships between mitochondrial swelling and cytochrome c release ... More
"Post-assay" covalent labeling of phosphorothioate-containing nucleic acids with multiple fluorescent markers.
AuthorsHodges RR, Conway NE, McLaughlin LW
JournalBiochemistry
PubMed ID2706249
'A simple protocol has been developed which allows the covalent introduction of multiple fluorescent markers into DNA fragments after gel electrophoresis techniques, that is, while the nucleic acid is imbedded in the polyacrylamide gel matrix. "Post-assay" fluorescent labeling in this manner employs DNA fragments containing phosphorothioate diesters, which can be ... More
High-throughput protein structural analysis using site-directed fluorescence labeling and the bimane derivative (2-pyridyl)dithiobimane.
AuthorsMansoor SE, Farrens DL
JournalBiochemistry
PubMed ID15260485
'We present a site-directed fluorescence labeling (SDFL) study of 25 different T4 lysozyme protein samples labeled with the thiol-cleavable fluorophore, (2-pyridyl)dithiobimane (PDT-Bimane). Our results demonstrate PDT-Bimane can be used in cysteine-scanning studies to detect protein secondary structure, and to map proximity between sites in proteins by monitoring tryptophan quenching of ... More
Low-molecular-weight thiols in streptomycetes and their potential role as antioxidants.
AuthorsNewton GL, Fahey RC, Cohen G, Aharonowitz Y
JournalJ Bacteriol
PubMed ID8478335
'The intracellular low-molecular-weight thiols present in five gram-positive Streptomyces species and one Flavobacterium species were analyzed by high-performance liquid chromatography after fluorescence labeling with monobromobimane. Bacteria were chosen to include penicillin and cephalosporin beta-lactam producers and nonproducers. No significant amount of glutathione was found in any of the streptomycetes. Major ... More
Dynamics of arrestin-rhodopsin interactions: acidic phospholipids enable binding of arrestin to purified rhodopsin in detergent.
AuthorsSommer ME, Smith WC, Farrens DL
JournalJ Biol Chem
PubMed ID16428804
'We report that acidic phospholipids can restore the binding of visual arrestin to purified rhodopsin solubilized in n-dodecyl-beta-d-maltopyranoside. We used this finding to investigate the interplay between arrestin binding and the status of the retinal chromophore ligand in the receptor binding pocket. Our results showed that arrestin can interact with ... More
Determination of reduced, oxidized, and protein-bound glutathione in human plasma with precolumn derivatization with monobromobimane and liquid chromatography.
AuthorsSvardal AM, Mansoor MA, Ueland PM
JournalAnal Biochem
PubMed ID2327578
'This assay measures reduced (GSH), oxidized (GSSG, GSSR), and protein-bound (glutathione-protein mixed disulfides, ProSSG) glutathione in human plasma. Oxidized glutathione and ProSSG are converted to GSH in the presence of NaBH4, and, after precolumn derivatization with monobromobimane, GSH is quantitated by reversed-phase liquid chromatography and fluorescence detection. The NaBH4 concentration ... More
Rhodopsin in reconstituted phospholipid vesicles. 2. Rhodopsin-rhodopsin interactions detected by resonance energy transfer.
AuthorsBorochov-Neori H, Fortes PA, Montal M
JournalBiochemistry
PubMed ID6830760
'The interactions between rhodopsin molecules in a micellar detergent solution (octyl glucoside) and in reconstituted phospholipid vesicles were studied in the dark and after bleaching. Resonance energy transfer measurements were used to monitor the proximity between rhodopsin monomers conjugated with a fluorescent donor or a fluorescent acceptor. Reactive sulfhydryl groups ... More
Methodologies for the application of monobromobimane to the simultaneous analysis of soluble and protein thiol components of biological systems.
AuthorsCotgreave IA, Moldéus P
JournalJ Biochem Biophys Methods
PubMed ID3805576
'A series of simple methodologies for the determination of the redox status of low molecular weight and protein thiols in biological systems is described. Based centrally upon the use of monobromobimane, we describe a standard in situ derivatisation procedure simultaneously resulting in maximal recovery of both free, reduced low molecular ... More
Structural implications of the chemical modification of Cys(10) on actin.
AuthorsEli-Berchoer L, Reisler E, Muhlrad A
JournalBiophys J
PubMed ID10692333
'Cys(10) is located in subdomain 1 of actin, which has an important role in the interaction of actin with myosin- and actin-binding proteins. Cys(10) was modified with fluorescence probes N-(iodoacetyl)N''-(5-sulfo-1-naphthyl)ethylene diamine (IAEDANS), 7-diethylamino-3-(4''-maleimidylphenyl)-4-methylcoumarin (CPM), or monobromo bimane (MBB) by the method of, J. Biol. Chem. 266:5508-5513). The specificity of Cys(10) ... More
Age and gender dependent levels of glutathione and glutathione S-transferases in human lymphocytes.
Authorsvan Lieshout EM, Peters WH
JournalCarcinogenesis
PubMed ID9806172
'Glutathione S-transferases (GSTs) are a family of enzymes involved in the detoxification of a wide range of chemicals including chemical carcinogens. Human cytosolic GSTs are divided into four major classes; alpha, mu, pi and theta. This study was performed to evaluate the influence of age and gender on the GST ... More
Glutathione monoethyl ester: high-performance liquid chromatographic analysis and direct preparation of the free base form.
AuthorsCampbell EB, Griffith OW
JournalAnal Biochem
PubMed ID2619045
'Glutathione monoethyl ester (L-gamma-glutamyl-L-cysteinylglycine ethyl ester) was shown by R. N. Puri and A. Meister (1983, Proc. Natl. Acad. Sci. USA 80, 5258-5260) to be taken up by several tissues and intracellularly hydrolyzed to GSH. Since GSH itself is not significantly taken up by tissues, glutathione monoesters provide the most ... More
The structure of U17 isolated from Streptomyces clavuligerus and its properties as an antioxidant thiol.
AuthorsNewton GL, Bewley CA, Dwyer TJ, Horn R, Aharonowitz Y, Cohen G, Davies J, Faulkner DJ, Fahey RC
JournalEur J Biochem
PubMed ID7607257
'The predominant low-molecular-mass thiol produced by streptomycetes is a cysteine derivative previously designated as U17 [Newton, G. L., Fahey, R. C., Cohen, G. & Aharonowitz, Y. (1993) J. Bacteriol. 175, 2734-2742]. In this study we report the elucidation of the structure of the monobromobimane derivative of U17, which establishes the ... More
Stabilization of the nuclear matrix by disulfide bridges: identification of matrix polypeptides that form disulfides.
AuthorsStuurman N, Floore A, Colen A, de Jong L, van Driel R
JournalExp Cell Res
PubMed ID1572396
'The molecular structure of the nuclear matrix is still poorly understood. We have tried to assess which proteins are important structural elements by examining the process of stabilization of the nuclear matrix by sodium tetrathionate. Sodium tetrathionate stabilizes the nuclear matrix by oxidizing sulfhydryl groups to disulfides. We show that ... More
Bimane fluorescent labels. Characterization of the bimane labeling of human hemoglobin.
AuthorsKosower NS, Newton GL, Kosower EM, Ranney HM
JournalBiochim Biophys Acta
PubMed ID7378449
'The products of the bimane labeling (using a monobromobimane, a dibromobimane and a quaternary bromobimane) of hemoglobin are characterized. Peptide mapping identifies cysteine-beta 93 as the reactive thiol site. Electrophoretic mobility of hemoglobin varies with the label used, that of monobromobimane-labeled hemoglobin being unaltered, while dibromobimane- and trimethylammoniobromobimane-labeled hemoglobin exhibit ... More
Nitric oxide reacts with intracellular glutathione and activates the hexose monophosphate shunt in human neutrophils: evidence for S-nitrosoglutathione as a bioactive intermediary.
'We performed experiments to determine whether nitric oxide promoted the formation of intracellular S-nitrosothiol adducts in human neutrophils. At concentrations sufficient to inhibit chemoattractant-induced superoxide anion production, nitric oxide caused a depletion of measurable intracellular glutathione as determined by both the monobromobimane HPLC method and the glutathione reductase recycling assay. ... More
Preferential substrate binding orientation by the molecular chaperone HscA.
AuthorsTapley TL, Vickery LE
JournalJ Biol Chem
PubMed ID15100228
'HscA, a specialized bacterial hsp70-class chaperone, interacts with the iron-sulfur cluster assembly protein IscU by recognizing a conserved LPPVK sequence motif at positions 99-103. We have used a site-directed fluorescence labeling and quenching strategy to determine whether HscA binds to IscU in a preferred orientation. HscA was selectively labeled on ... More
A sensitive high-performance liquid chromatographic method for the determination of 6-mercaptopurine in plasma using precolumn derivatization and fluorescence detection.
AuthorsWarren DJ, Slørdal L
JournalTher Drug Monit
PubMed ID8451776
'A sensitive high-performance liquid chromatographic (HPLC) method for measuring plasma concentrations of 6-mercaptopurine (6-MP) is described. After protein precipitation with 5-sulfosalicylic acid, samples are subjected to precolumn derivatization using the thiol-reactive fluorophore monobromobimane (mBrB). The drug-mBrB adduct is then resolved by isocratic elution from a C18 reversed-phase support and quantified ... More
Doubly-lipid-modified protein sequence motifs exhibit long-lived anchorage to lipid bilayer membranes.
AuthorsShahinian S, Silvius JR
JournalBiochemistry
PubMed ID7893678
'To understand better the potential functional importance of the dual-lipid modifications found in a number of intracellular proteins of eukaryotes, we have examined how "tenaciously" various doubly-lipid-modified peptides, with sequences and lipid modifications reflecting those found in intracellular proteins, are anchored to lipid bilayer membranes. Fluorescent-labeled peptides bearing dual-lipid modifications ... More
Lipid-modified, cysteinyl-containing peptides of diverse structures are efficiently S-acylated at the plasma membrane of mammalian cells.
AuthorsSchroeder H, Leventis R, Shahinian S, Walton PA, Silvius JR
JournalJ Cell Biol
PubMed ID8707845
'A variety of cysteine-containing, lipid-modified peptides are found to be S-acylated by cultured mammalian cells. The acylation reaction is highly specific for cysteinyl over serinyl residues and for lipid-modified peptides over hydrophilic peptides. The S-acylation process appears by various criteria to be enzymatic and resembles the S-acylation of plasma membrane-associated ... More
SV40 large T-antigen nuclear signal analogues: successful nuclear targeting with bovine serum albumin but not low molecular weight fluorescent conjugates.
AuthorsLobl TJ, Mitchell MA, Maggiora LL
JournalBiopolymers
PubMed ID2328286
'The signal sequence of a nuclear-directed protein encodes the necessary information for targeting the attached proteins to the cell nucleus. The sequence/structural requirements for a functional transport signal were explored with a series of peptides derived from the simian virus 40 large T-antigen nuclear signal 126-134 (CPKKKRKVED-NH2, wild type) conjugated ... More
Simultaneous analysis of relative DNA and glutathione content in viable cells by phase-resolved flow cytometry.
AuthorsKeij JF, Bell-Prince C, Steinkamp JA
JournalCytometry
PubMed ID10554180
'BACKGROUND: Analysis of the DNA cell cycle and glutathione content cannot be performed on viable cells, because the fluorescence emissions of the DNA-specific probe Hoechst 33342 and the glutathione-specific probe monobromobimane overlap completely. We decided to explore whether the emissions could be resolved by the singlet excited state lifetimes of ... More
Phytochelatin synthase catalyzes key step in turnover of glutathione conjugates.
AuthorsBeck A, Lendzian K, Oven M, Christmann A, Grill E
JournalPhytochemistry
PubMed ID12620355
'Conjugation of xenobiotic compounds and endogenous metabolites to glutathione is an ubiquitous process in eukaryotes. In animals, the first and rate-limiting step of glutathione-S-conjugate metabolism is characterized by the removal of the aminoterminal glutamic acid residue of glutathione. In plants, however, glutathione-S-conjugates are generally metabolized by removal of the carboxylterminal ... More
Profile of the disulfide bonds in acetylcholinesterase.
AuthorsMacPhee-Quigley K, Vedvick TS, Taylor P, Taylor SS
JournalJ Biol Chem
PubMed ID3759980
'The inter- and intrasubunit disulfide bridges for the 11 S form of acetylcholinesterase isolated from Torpedo californica have been identified. Localized within the basal lamina of the synapse, the dimensionally asymmetric forms of acetylcholinesterase contain either two (13 S) or three (17 S) sets of catalytic subunits linked to collagenous ... More
Patterns of mutagen binding and penetration in multicell spheroids.
AuthorsOlive PL
JournalEnviron Mutagen
PubMed ID3095108
'Mutagen damage to a cell located at some distance from the site of application of the mutagen will depend, in part, on how effectively it can penetrate through cells composing different tissues. Chinese hamster V79 spheroids were used to model mutagen "penetrability" by providing several layers of cells growing with ... More
Measurement of glutathione levels in intact roots of Arabidopsis.
AuthorsFricker MD, May M, Meyer AJ, Sheard N, White NS
JournalJ Microsc
PubMed ID10849194
'Levels of glutathione were measured for different cell types in roots of intact Arabidopsis seedlings after labelling with monochlorobimane to give fluorescent glutathione S-bimane (GSB) and imaging using confocal laser scanning microscopy with excitation at 442 nm. Labelling increased to a plateau in most cell types after about 15-20 min ... More
The use of monochlorobimane to determine hepatic GSH levels and synthesis.
AuthorsFernández-Checa JC, Kaplowitz N
JournalAnal Biochem
PubMed ID2291468
'We have used the specific reaction of monochlorobimane (mBCI) with GSH to analyze hepatic GSH, mBCI, itself nonfluorescent, forms a stable, fluorescent adduct with GSH in a reaction catalyzed by the GSH S-transferases (GST). When hepatocytes were labeled with mBC1 (100 microM) in Krebs-Henseleit buffer, the fluorescent signal recorded over ... More
Resonance energy transfer between sites in rat liver glutathione S-transferase, 1-1, selectively modified at cysteine-17 and cysteine-111.
AuthorsHu L, Colman RF
JournalBiochemistry
PubMed ID9048547
'Monobromobimane (mBBr) can label both Cys111 and Cys17 of rat liver glutathione S-transferase, 1-1 (GST 1-1). However, selective modification of Cys111 was achieved by the maleimide-based sulfhydryl reagents N-ethylmaleimide (NEM) and fluorescein 5-maleimide (NFM). Incubation of GST 1-1 with 5 mM NEM for 30 min at pH 7.5 and 25 ... More
Fluorometric determination of 2,3-dimercaptopropane-1-sulfonic acid and other dithiols by precolumn derivatization with bromobimane and column liquid chromatography.
AuthorsMaiorino RM, Weber GL, Aposhian HV
JournalJ Chromatogr
PubMed ID3958088
'The increasing therapeutic use of dithiol metal binding agents, such as 2,3-dimercaptopropane-1-sulfonic acid (DMPS), has stimulated the need for a sensitive and selective method for their determination in biological fluids. A method has now been developed in which DMPS was converted to a highly fluorescent and stable derivative by reaction ... More
Binding of destabilized betaB2-crystallin mutants to alpha-crystallin: the role of a folding intermediate.
AuthorsSathish HA, Koteiche HA, McHaourab HS
JournalJ Biol Chem
PubMed ID14761939
'Age-related changes in protein-protein interactions in the lens play a critical role in the temporal evolution of its optical properties. In the relatively non-regenerating environment of the fiber cells, a critical determinant of these interactions is partial or global unfolding as a consequence of post-translational modifications or chemical damage to ... More
Thiol levels in CD134-defined subsets of rat T lymphocytes: possible implications for HgCl2-induced immune dysregulation.
AuthorsRoos A, Claessen N, Schilder-Tol EJ, Chand MA, Weening JJ, Aten J
JournalBiochem Biophys Res Commun
PubMed ID9388500
'CD134 (OX40), a member of the tumour necrosis factor receptor family, is expressed on activated T cells and mediates T and B cell costimulation. Its expression is increased after exposure to the thiol-binding compound HgCl2 in BN rats, but not in Lewis rats, in association with induction of a T ... More
Thiols in oxidative phosphorylation: inhibition and energy-potentiated uncoupling by monothiol and dithiol modifiers.
AuthorsYagi T, Hatefi Y
JournalBiochemistry
PubMed ID6477876
'Three apparently different modifications of submitochondrial particles (SMP) or ATP synthase preparations (complex V) inhibit oxidative phosphorylation and ATP-32Pi exchange activities, all of which are reversible by addition of mono- or dithiols. (a) Triphenyltin chloride inhibits ATP synthesis and hydrolysis without uncoupling. The inhibition by triphenyltin chloride is reversible by ... More
Identification of a major low-molecular-mass thiol of the trypanosomatid Crithidia fasciculata as ovothiol A. Facile isolation and structural analysis of the bimane derivative.
AuthorsSteenkamp DJ, Spies HS
JournalEur J Biochem
PubMed ID8033907
'An unidentified low-molecular-mass thiol, U23, previously detected as the 7-diethylamino-3-(4''-maleimidylphenyl)-4-methylcoumarin derivative in extracts of the trypanosome Crithidia fasciculata, was purified as the bimane derivative. Resonances attributable to U23 were discerned from those of the bimane label by comparison of the 1H- and 13C-NMR spectra of monobromobimane and U23-bimane. The complete ... More
Identification of coenzyme M biosynthetic phosphosulfolactate synthase: a new family of sulfonate-biosynthesizing enzymes.
Authors Graham David E; Xu Huimin; White Robert H;
JournalJ Biol Chem
PubMed ID11830598
'The hyperthermophilic euryarchaeon Methanococcus jannaschii uses coenzyme M (2-mercaptoethanesulfonic acid) as the terminal methyl carrier in methanogenesis. We describe an enzyme from that organism, (2R)-phospho-3-sulfolactate synthase (ComA), that catalyzes the first step in coenzyme M biosynthesis. ComA catalyzed the stereospecific Michael addition of sulfite to phosphoenolpyruvate over a broad range ... More
Effects of monochlorobimane on cerebral ischemia-induced damage to mitochondria.
AuthorsOshikawa S, Miyake-Takagi K, Takagi N, Abe T, Kuruhara Y, Takeo S
JournalBiol Pharm Bull
PubMed ID14758026
'A possible involvement of inhibitory effects of monochlorobimane (MCB) on the opening of mitochondrial permeability transition (MPT) pore in the cerebroprotection against the ischemic brain injury was examined. MCB (1 mM) inhibited the opening of MPT pore in vitro. Sustained cerebral ischemia was induced by injecting 900 microspheres (48 microm ... More
Influence of pH on sulfhydryl groups and fluidity of the mitochondrial membrane.
AuthorsZimmer G, Freisleben HJ, Fuchs J
JournalArch Biochem Biophys
PubMed ID2173480
'Fluidity of the red blood cell membrane decreases as pH changes from 8 to 7.5. In rat liver mitochondrial (RLM) membrane fluidity precipitously declines as pH drops from 7.35 toward 7.0. With dithionitrobenzoate (Nbs2), reaction rates of mitochondrial -SH groups from rat liver and heart (RHM) and in beef heart ... More
Modification of platelet functions by monobromobimane, a fluorescent thiol group label.
AuthorsZucker MB, Mauss EA
JournalThromb Haemost
PubMed ID3012818
'Monobromobimane (mBBr, bimane), a compound that penetrates cells and forms a fluorescent adduct with thiol groups, was used to asses the significance of thiols in platelet function. Exposure of washed platelets for 1 min to 100 microM mBBr abolished ADP-induced aggregation; shape change was not inhibited by 500 microM mBBr. ... More
Resonance energy transfer: methods and applications.
AuthorsWu P, Brand L
JournalAnal Biochem
PubMed ID8053542
'Resonance energy transfer is widely used in studies of biomolecular structure and dynamics. It provides information about distances on the order of 10 to 100 A and is thus suitable for investigating spatial relationships of interest in biochemistry. The information available from energy transfer studies has been enhanced by the ... More
An in situ study of metal complexation by an immobilized synthetic biopolymer using tapping mode liquid cell atomic force microscopy.
AuthorsMiller TC, Kwak ES, Howard ME, Vanden Bout DA, Holcombe JA
JournalAnal Chem
PubMed ID11569796
'Near-field scanning optical microscopy and tapping mode, liquid cell atomic force microscopy were used to study the conformational changes in simple short-chain silica-immobilized biopolymer, poly(L-cysteine) (PLCys), as the polymer was exposed to reducing, metal-rich, and acidic environments, respectively, to simulate on-line metal preconcentration. In a reducing environment (0.01 M dithiothreitol ... More
Aggregation, lipid exchange, and metastable phases of dimyristoylphosphatidylethanolamine vesicles.
AuthorsPryor C, Bridge M, Loew LM
JournalBiochemistry
PubMed ID3995010
'A new fluorescent lipid analogue, bimanephosphatidylcholine, has been synthesized for use in lipid bilayers. This probe is well suited as an energy-transfer donor with N-(7-nitro-2,1,3-benzoxadiazol-4-yl)phosphatidylethanolamine as the acceptor. Dimyristoylphosphatidylethanolamine vesicles are prepared by sonication at pH 9 and characterized by electron microscopy and other methods. Resonance energy transfer between separately ... More
Interaction of glucose and metformin with isolated red cell membrane.
AuthorsFreisleben HJ, Fürstenberger HJ, Deisinger S, Freisleben KB, Wiernsperger N, Zimmer G
JournalArzneimittelforschung
PubMed ID9125277
'Isolated human erythrocyte membranes (red blood cell (RBC) ghosts) were incubated with glucose at 5, 10, 20 and 100 mmol/l concentrations, with insulin (0.01 to 200 mU/l) and metformin (CAS 657-24-9) 0.5 up to 50.0 mumol/l). Binding studies with 14C-glucose and subsequent gel electrophoresis revealed 60% of the radioactivity around ... More
Two-dimensional polyacrylamide gel electrophoresis of proteins labeled with the fluorophore monobromobimane prior to first-dimensional isoelectric focusing: imaging of the fluorescent protein spot patterns using a cooled charge-coupled device.
AuthorsUrwin VE, Jackson P
JournalAnal Biochem
PubMed ID8465962
'A new method for visualizing 2D protein spot patterns is described whereby proteins containing sulfhydryl groups are labeled with the fluorophore monobromobimane prior to the isoelectric focusing step of 2D polyacrylamide gel electrophoresis. The method requires the addition of a single reagent and a delay of only 15 min during ... More
Mitochondrial membrane sensitivity to depolarization in acute myeloblastic leukemia is associated with spontaneous in vitro apoptosis, wild-type TP53, and vicinal thiol/disulfide status.
AuthorsPallis M, Grundy M, Turzanski J, Kofler R, Russell N
JournalBlood
PubMed ID11435310
'Nonresponse to remission-induction chemotherapy, which remains a major problem in acute myeloblastic leukemia (AML), has been linked to cellular resistance to apoptosis. Because the apoptosis induced by chemotherapeutic drugs is mediated by loss of mitochondrial transmembrane potential (MTP), it was postulated that sensitivity to mitochondrial membrane depolarization might be heterogeneous ... More
Intracellular glutathione in the peripheral blood cells of HIV-infected patients: failure to show a deficiency.
AuthorsPirmohamed M, Williams D, Tingle MD, Barry M, Khoo SH, O'Mahony C, Wilkins EG, Breckenridge AM, Park BK
JournalAIDS
PubMed ID8724041
'OBJECTIVE: To determine whether HIV-infected patients have a deficiency of intracellular glutathione (GSH) in peripheral blood mononuclear cells (PBMC) and erythrocytes. DESIGN: Initial experiments determining the stability of intracellular GSH preceded the measurement of GSH levels in 33 HIV-positive patients and 40 control subjects within 1 h of isolation of ... More
Cadmium-induced apoptosis in C6 glioma cells: influence of oxidative stress.
AuthorsWätjen W, Beyersmann D
JournalBiometals
PubMed ID14977363
'Cadmium has recently been shown to induce apoptosis in C6 glioma cells via disruption of the mitochondrial membrane potential and subsequent caspase 9-activation. Here we show that both H2O2 and CdCl2 induced apoptotic DNA fragmentation in C6 cells. The employment of glutathione as an antioxidant prevented the induction of apoptotic ... More
L-Homocysteine and L-homocystine stereospecifically induce endothelial nitric oxide synthase-dependent lipid peroxidation in endothelial cells.
AuthorsHeydrick SJ, Weiss N, Thomas SR, Cap AP, Pimentel DR, Loscalzo J, Keaney JF
JournalFree Radic Biol Med
PubMed ID14980706
'Atherothrombotic cardiovascular disease associated with hyperhomocysteinemia has been proposed to result, at least in part, from increased vascular oxidative stress. Here we characterize one mechanism by which homocyteine may induce a vascular cell type-specific oxidative stress. Our results show that L-homocysteine at micromolar levels stereospecifically increases lipid peroxidation in cultured ... More
Disulfide formation in bovine zona pellucida glycoproteins during fertilization: evidence for the involvement of cystine cross-linkages in hardening of the zona pellucida.
AuthorsIwamoto K, Ikeda K, Yonezawa N, Noguchi S, Kudo K, Hamano S, Kuwayama M, Nakano M
JournalJ Reprod Fertil
PubMed ID10690208
'The time for solubilization of the bovine zona pellucida in a hypotonic buffer containing 5% (v/v) beta-mercaptoethanol and 7 mol urea l-1 increased by 10% after fertilization. Coupling with a specific fluorescent thiol probe, monobromobimane (mBBr), was markedly greater in the zona pellucida of ovarian eggs compared with fertilized eggs, ... More
In vivo monitoring of glutathione and cysteine in rat caudate nucleus using microdialysis on-line with capillary zone electrophoresis-laser induced fluorescence detection.
AuthorsLada MW, Kennedy RT
JournalJ Neurosci Methods
PubMed ID9133579
'A fully-automated method for monitoring thiols in vivo using microdialysis coupled on-line with capillary zone electrophoresis with laser-induced fluorescence detection was developed. Dialysates were derivatized on-line with monobromobimane and automatically transferred to the separation capillary by a flow-gated interface. Analytes were detected on-column using the 2 mW, 354 nm line ... More
An oxidative stress-mediated death pathway in irradiated human leukemia cells mapped using multilaser flow cytometry.
AuthorsSheng-Tanner X, Bump EA, Hedley DW
JournalRadiat Res
PubMed ID9840183
'OCI/AML-2 acute myeloid leukemia cells were found to undergo apoptosis after treatment with y rays from a 137Cs source. Multilaser flow cytometry techniques using probes for live cell function were used to monitor the biochemical changes that occurred prior to the loss of surface membrane integrity. These showed increases in ... More
Detection technologies in proteome analysis.
AuthorsPatton WF
JournalJ Chromatogr B Analyt Technol Biomed Life Sci
PubMed ID12015990
'Common strategies employed for general protein detection include organic dye, silver stain, radiolabeling, reverse stain, fluorescent stain, chemiluminescent stain and mass spectrometry-based approaches. Fluorescence-based protein detection methods have recently surpassed conventional technologies such as colloidal Coomassie blue and silver staining in terms of quantitative accuracy, detection sensitivity, and compatibility with ... More
Vacuolar accumulation and extracellular extrusion of electrophilic compounds by wild-type and glutathione-deficient mutants of the methylotrophic yeast Hansenula polymorpha.
AuthorsUbiyvovk VM, Maszewski J, Bartosz G, Sibirny AA
JournalCell Biol Int
PubMed ID12972285
'The methylotrophic yeast Hansenula polymorpha CBS4732 leu2 detoxifies electrophilic xenobiotics by glutathione (GSH)-dependent accumulation in vacuoles, as shown by fluorescence microscopy. GSH-dependent and GSH-independent export of xenobiotic derivatives were also demonstrated by high-performance liquid chromatography (HPLC). Conjugates of GSH and N-acetylcysteine with monobromobimane and N-[1-pyrene]maleimide were observed among the HPLC ... More
Structural plasticity of an acid-activated chaperone allows promiscuous substrate binding.
AuthorsTapley TL, Körner JL, Barge MT, Hupfeld J, Schauerte JA, Gafni A, Jakob U, Bardwell JC,
JournalProc Natl Acad Sci U S A
PubMed ID19321422
'HdeA has been shown to prevent acid-induced aggregation of proteins. With a mass of only 9.7 kDa, HdeA is one of the smallest chaperones known. Unlike other molecular chaperones, which are typically complex, multimeric ATP-dependent machines, HdeA is known to undergo an acid-induced dimer to monomer transition and functions at ... More
Ferrochelatase from Rhodopseudomonas sphaeroides: substrate specificity and role of sulfhydryl and arginyl residues.
AuthorsDailey HA, Fleming JE, Harbin BM
JournalJ Bacteriol
PubMed ID3484475
'Purified ferrochelatase (protoheme ferrolyase; EC 4.99.1.1) from the bacterium Rhodopseudomonas sphaeroides was examined to determine the roles of cationic and sulfhydryl residues in substrate binding. Reaction of the enzyme sulfhydryl residues with N-ethylmaleimide or monobromobimane resulted in a rapid loss of enzyme activity. Ferrous iron, but not porphyrin substrate, had ... More
A brief survey of methods for preparing protein conjugates with dyes, haptens, and cross-linking reagents.
AuthorsBrinkley M
JournalBioconjug Chem
PubMed ID1616945
Measurement of plasma thiols after derivatization with monobromobimane.
AuthorsVelury S, Howell SB
JournalJ Chromatogr
PubMed ID3366825
Derivatization of thiol-containing compounds.
AuthorsShimada K, Mitamura K
JournalJ Chromatogr B Biomed Appl
PubMed ID7820279
'The determination of thiol-containing compounds in biological fluids is important in biochemistry and clinical chemistry. In this paper, derivatization reagents for thiols are reviewed with respect to their reactivity, selectivity, spectroscopic characteristics and their applicability especially to high-performance liquid chromatography. Derivatization used in ultraviolet and electrochemical detection. The derivatization reagents ... More
HPLC screening method for cystinuria.
AuthorsLivesey JF, Donnelly JG, Ooi DS
JournalClin Chem
PubMed ID8855161
A novel method for the quantitation of 6-mercaptopurine in human plasma using high-performance liquid chromatography with fluorescence detection.
AuthorsBurton NK, Aherne GW, Marks V
JournalJ Chromatogr
PubMed ID6541226
Selective inhibition of the mitochondrial permeability transition pore at the oxidation-reduction sensitive dithiol by monobromobimane.
AuthorsCostantini P, Chernyak BV, Petronilli V, Bernardi P
JournalFEBS Lett
PubMed ID7536690
'In this paper we introduce monobromobimane, a thiol reagent, as a selective blocker of the recently identified dithiol whose oxidation-reduction status modifies voltage sensing by the mitochondrial permeability transition pore, a cyclosporin A-sensitive channel. Monobromobimane does not inhibit the phosphate carrier, nor does it interfere with Ca2+ transport, energy coupling ... More
Effect of sulfhydryl group modification on the activity of bovine ferrochelatase.
AuthorsDailey HA
JournalJ Biol Chem
PubMed ID6698990
'The role of sulfhydryl groups in the activity of the terminal enzyme of the heme biosynthetic pathway, ferrochelatase (protoheme ferrolyase, EC 4.99.1.1), has been examined by using a variety of sulfhydryl group-specific reagents. The enzyme is rapidly inactivated in a pseudo-first order reaction by N-ethylmaleimide and monobromobimane and more slowly ... More
The preparation and application of functionalised synthetic oligonucleotides: III. Use of H-phosphonate derivatives of protected amino-hexanol and mercapto-propanol or -hexanol.
AuthorsSinha ND, Cook RM
JournalNucleic Acids Res
PubMed ID3362678
'Syntheses of H-phosphonate salts (4a-e) of N/S-protected alcohols such as 6-aminohexan-1-ol, 3-mercaptopropan-1-ol and 6-mercaptohexan-1-ol are described using 2-chloro-5,6-benzo-1,3,2-phosphorin-4-one (2) as the phosphonylating agent. The H-phosphonate salts (4a-e), in the presence of pivaloyl chloride or adamantoyl chloride as an activator, were coupled to the 5''-end of synthetic oligonucleotides on solid supports ... More
20 S proteasome from Saccharomyces cerevisiae is responsive to redox modifications and is S-glutathionylated.
AuthorsDemasi M, Silva GM, Netto LE
JournalJ Biol Chem
PubMed ID12409293
'The 20 S proteasome core purified from Saccharomyces cerevisiae is inhibited by reduced glutathione (GSH), cysteine (Cys), or the GSH precursor gamma-glutamylcysteine. Chymotrypsin-like activity was more affected by GSH than trypsin-like activity, whereas the peptidylglutamyl-hydrolyzing activity (caspase-like) was not inhibited by GSH. Cys-sulfenic acid formation in the 20 S core ... More
Chelerythrine stimulates GSH transport by rat Mrp2 (Abcc2) expressed in canine kidney cells.
AuthorsLou H, Ookhtens M, Stolz A, Kaplowitz N
JournalAm J Physiol Gastrointest Liver Physiol
PubMed ID12893631
'Rat multidrug resistant protein 2 (Mrp2; Abcc2), an ATP-driven pump located on the canalicular domain of hepatocytes, exports glutathione S-conjugates (GS-X) and GSH among its wide variety of substrates. Previous studies have shown that chelerythrine (CHEL), a quaternary benzophenanthridine cation, reacts with GSH to form a reversible adduct under physiological ... More
The effects of monobromobimane on neuronal cell death in the hippocampus after transient global cerebral ischemia in rats.
AuthorsAbe T, Takagi N, Nakano M, Takeo S
JournalNeurosci Lett
PubMed ID15003291
'Calcium accumulation and free radical formation in the mitochondria are suggested to result in opening of the mitochondrial permeability transition pore that may be an initial step in neuronal cell death. The purpose of the present study was to determine whether monobromobimane (MBM) was a possible protective agent against neuronal ... More
Use of N-acetyl cysteine to increase intracellular glutathione during the induction of antitumor responses by IL-2.
AuthorsYim CY, Hibbs JB, McGregor JR, Galinsky RE, Samlowski WE
JournalJ Immunol
PubMed ID8207209
'IL-2 therapy can induce marked oxidative stress via reactive oxygen and nitrogen intermediates. Glutathione, the major intracellular reductant, may become rate limiting to cytotoxic lymphocyte activation and proliferation under these circumstances. N-Acetyl cysteine (NAc-cys) was used to increase intracellular glutathione levels during lymphokine-activated killer (LAK) cell activation by IL-2. Incubation ... More
A glutathione reductase mutant of yeast accumulates high levels of oxidized glutathione and requires thioredoxin for growth.
AuthorsMuller EG
JournalMol Biol Cell
PubMed ID8930901
'A glutathione reductase null mutant of Saccharomyces cerevisiae was isolated in a synthetic lethal genetic screen for mutations which confer a requirement for thioredoxin. Yeast mutants that lack glutathione reductase (glr1 delta) accumulate high levels of oxidized glutathione and have a twofold increase in total glutathione. The disulfide form of ... More
Unraveling thioredoxin-linked metabolic processes of cereal starchy endosperm using proteomics.
AuthorsWong JH, Balmer Y, Cai N, Tanaka CK, Vensel WH, Hurkman WJ, Buchanan BB
JournalFEBS Lett
PubMed ID12860404
'Application of a thiol-specific probe, monobromobimane, with proteomics and enzyme assays led to the identification of 23 thioredoxin targets in the starchy endosperm of mature wheat seeds (Triticum aestivum cv. Butte), almost all containing at least two conserved cysteines. The identified targets, 12 not known to be thioredoxin-linked, function in ... More
Transport of glutathione S-conjugates in Escherichia coli.
AuthorsKaluzna A, Bartosz G
JournalBiochem Mol Biol Int
PubMed ID9315294
'There are no reports concerning glutathione-S-conjugates transport in prokaryotic cells, although many studies have been performed in eukaryotic systems. This study demonstrates that glutathione S-conjugates (2,4-dinitrophenyl-S-glutathione and bimane-S-glutathione) are transported also out of Escherichia coli K12 cells. This transport is inhibited by vanadate, fluoride and other inhibitors of glutathione S-conjugate ... More
Stabilising and destabilising modifications of cysteines in the E. coli outer membrane porin protein OmpC.
AuthorsGokce I, Bainbridge G, Lakey JH
JournalFEBS Lett
PubMed ID9271205
'Three sulfhydryl labels were used to modify two mutated sites, R37C and R74C in the eyelet of the outer membrane porin OmpC. Modification of R37C with the neutral groups Aldrithiol and bimane increases thermal stability but the negatively charged iodoacetate causes a decrease in thermal stability. The effects of substitution ... More
Sulfhydryl reagents induce altered spectrin self-association, skeletal instability, and increased thermal sensitivity of red cells.
AuthorsSmith DK, Palek J
JournalBlood
PubMed ID6640108
'Incubation of erythrocytes with the sulfhydryl reagent N-ethyl-maleimide (NEM) results in altered spectrin self-association and formation of dimers on the membrane. Skeletons isolated from these cells exhibit marked skeletal instability. In addition, NEM treatment induces increased thermal sensitivity of both cells and purified spectrin. These effects were not produced in ... More
Process patent bill on track.
AuthorsGershon D
JournalNature
PubMed ID8332176
Monobromobimane: a substrate for the fluorimetric assay of glutathione transferase.
AuthorsHulbert PB, Yakubu SI
JournalJ Pharm Pharmacol
PubMed ID6135779
Thioredoxin and seed proteins.
AuthorsWong JH, Kobrehel K, Buchanan BB
JournalMethods Enzymol
PubMed ID7476357
New fluorogenic substrates for microdetermination of carboxypeptidase A.
AuthorsSato E, Kanaoka Y
JournalChem Pharm Bull (Tokyo)
PubMed ID3246016
Determination of low-molecular-weight thiols using monobromobimane fluorescent labeling and high-performance liquid chromatography.
AuthorsFahey RC, Newton GL
JournalMethods Enzymol
PubMed ID3657565
New fluorogenic substrates for microdetermination of cathepsin C.
AuthorsSato E, Matsuda K, Kanaoka Y
JournalChem Pharm Bull (Tokyo)
PubMed ID2268911
Assay of gamma-glutamylcysteine synthetase and glutathione synthetase in erythrocytes by high-performance liquid chromatography with fluorimetric detection.
AuthorsNardi G, Cipollaro M, Loguercio C
JournalJ Chromatogr
PubMed ID1980497
Analysis of biological thiols: quantitative determination of thiols at the picomole level based upon derivatization with monobromobimanes and separation by cation-exchange chromatography.
AuthorsFahey RC, Newton GL, Dorian R, Kosower EM
JournalAnal Biochem
PubMed ID7247030
Determination of biothiols by bromobimane labeling and high-performance liquid chromatography.
AuthorsNewton GL, Fahey RC
JournalMethods Enzymol
PubMed ID7651194
An improved monobromobimane assay for glutathione utilizing tris- (2-carboxyethyl)phosphine as the reductant.
Glutathione and cellular resistance to anti-cancer drugs.
AuthorsHedley D, Chow S
JournalMethods Cell Biol
PubMed ID7533246
Thiol labeling with bromobimanes.
AuthorsKosower NS, Kosower EM
JournalMethods Enzymol
PubMed ID3657564
Structure of actin observed by fluorescence resonance energy transfer spectroscopy.
AuthorsMiki M, O'Donoghue SI, Dos Remedios CG
JournalJ Muscle Res Cell Motil
PubMed ID1534564
Reductive dehalogenation of monobromobimane by tris(2-carboxyethyl)phosphine.
AuthorsGraham DE, Harich KC, White RH,
JournalAnal Biochem
PubMed ID12814640
We demonstrate that the primary fluorescent product of the TCEP reaction with monobromobimane is the 9,10-dioxa-syn-(methyl,methyl)(methyl,methyl)bimane, formed by an unusual nucleophilic attack of the phosphine on the monobromobimane bromine atom. ... More